The story is about a Nazi doctor and escaped prisoner-of-war who goes to London. There, via the Nazi underground, he poses as an Australian bacteriologist, whom he has killed and taken his place, assigned to do some medical research. His plot is, using British labs and knowledge, to find a method of immunizing the German people against a plague the Nazis are going to use in their next war. Complications arise when his British assistant, Robert Beatty, becomes suspicious of his actions, and an Australian girl who knew the real doctor shows up. Starring Robert Beatty, Mervyn Johns, and Nova Pilbeam. An interesting British thriller made only a few years after WWII.
